The lymphatic system is a part of the human body's circulatory system. Through a complex network of lymph nodes and vessels, it transports and removes lymph fluid, which is a clear, high protein fluid, from the spaces between cells of the body. More specifically, the lymphatic system acts as a waste removal system for the body, removing metabolic wastes from the body's cells and then transporting that waste to the lymph nodes for filtering and detoxification. The “clean” lymph fluid is then returned to the bloodstream.
The lymphatic system, however, also serves as a conduit for cancerous cells to flow from a primary tumor to other sites. Consequently, lymph node biopsy is commonly used as a diagnostic procedure to determine the status of the cancer and to check to see if it has spread. Moreover, should the patient require surgery to remove cancerous sites, a surgeon may also have to remove lymph nodes and vessels from the affected area, such as the axilla (arm pit) and breast area in the case of breast cancer.
The removal of nodes and vessels in the affected area can compromise the local integrity of the lymphatic system, thereby adversely impacting lymphatic drainage. Radiation therapy can also damage or destroy lymphatic components, thereby further contributing to lymphatic compromise. The natural aging process may also contribute to lymphatic breakdown.
Impairment of the lymphatic system can radically reduce its capacity to transport, filter, and detoxify lymph fluid. It can also change the way that lymph fluid flows in that quadrant of the human body. Over time, sometimes years later, the lymph system can fail and fluid can back up, thereby causing swelling in a localized area. Greater fluid retention in the tissue also increases the risk that the patient will develop an infection, as one of the functions of the lymphatic system is to carry away and filter any bacteria that may be present in the lymph fluid.
Chronic swelling caused by the accumulation of lymph fluid in an area of the body is called lymphedema, a condition that is common among post-mastectomy patients and other cancer survivors who have had lymph nodes or vessels removed, or who have undergone radiation therapy. Lymphedema typically occurs in a limb (such as an arm), but it can also occur in the torso region, especially among breast cancer survivors. It may be characterized by swelling, heaviness, pain, pitting, tightness, or hardness of the tissues.
There are three stages of lymphedema, ranging from mild lymphedema, where the tissue may present with “pitting” (where the tissue, when pressed, will indent and hold the indention briefly) that is temporary and resolves overnight, to severe lymphedema (which is sometimes known as elephantitis), where the tissue increases in hardness or fibrosis and the swelling can be disfiguring and does not reverse itself. As with most medical conditions, it is desirable that lymphedema be diagnosed and treated as soon as possible, so as hopefully to prevent or at least retard progression of the condition from the mild to severe stages.
Treatment for lymphedema typically focuses on lymphatic drainage techniques and/or the use of compression garments, although proper skin care, exercise, and, where there is an infection, antibiotic therapy, can also be important components of a treatment plan. With lymphatic drainage techniques, which include “manual lymphatic drainage” and “simple lymphatic drainage,” the patient or a therapist gently massages the connective tissue in specific directions in accordance with the structure and physiology of the lymphatic system, thereby stimulating the weakened system by pushing the stagnant fluid through the vessels. This also allows the venous system to reabsorb the fluid and helps establish channels through which lymph fluid can flow.
Compression garments may be used as an adjunct to, or as an alternative for, lymphatic drainage, depending on the severity of the condition. Compression garments are designed to apply external pressure to an affected area, thereby helping to maintain the size of that area so that swelling remains reduced. A compression garment can also improve the pumping of lymphatics and veins as well by creating a firm abutment for muscles to work against. Another benefit of a compression garment is that it reduces local blood volume in the veins, which in turn results in increased velocity in the vein and greater fluid throughput.
The most common types of compression garments are compression stockings or sleeves, which garments typically have to be expertly fit to the patient or, in some instances, custom made. Due to the complexities inherent in delivering the appropriate amounts of compression to various regions of the torso, however, few compression garments have been provided for use in the torso region, and even fewer exist that do not have to be custom made.
One such design is disclosed in U.S. Pat. No. 5,800,245 to Barbe-Vicuna et al. In this patent, Barbe-Vicuna et al. disclose a compression bra that uses a system of compression pads and cushions to increase pressure at certain desired locations on the torso, thereby purportedly facilitating and/or consolidating the benefits of manual lymphatic drainage. The disclosed garment, however, does not appear to deliver any overall compression to the torso beyond that of a typical brassiere. Instead, the Barbe-Vicuna et al. brassiere is limited to providing increased levels of compression at specific areas (namely, at the sites of the compression pads).
Another garment that is designed to provide compression to a wearer's breasts is disclosed in U.S. Pat. No. 5,839,942 to Miller. In this patent, Miller discloses a bra that is designed to treat post-partum engorgement, enlargement, and other conditions by delivering an adjustable level of compression, as well as by providing for the proper positioning of warm or cold compresses. The bra is fabricated from two layers of resilient material to provide compression and envelopment of the breasts. The overall design of this bra, however, would not be appropriate for the treatment of lymphedema, nor could it provide varying amounts of compression at different areas of the torso.
Finally, a large number of garments have been provided in the past that are designed to control breast motion (such as sports bras), provide invisible support under other garments (such as shelf bras), enhance the appearance of breasts (such as “push-up” bras), or some combination thereof (such as most “mainstream” bras). Examples of these garments are disclosed in U.S. Pat. Nos. 6,168,498; 4,440,174; and 5,868,601 (among others), as well as in the references cited therein. None of these garments, however, disclose the garment of the claimed invention. Similarly, the garment disclosed in U.S. Pat. Nos. 6,086,450 and 6,361,397, which supposedly facilitate the drainage of lymphatic fluid from the breast area, are far removed from Applicant's design.